Polarized electrical relay



Patented Nov. 23, 1948 POLRIZED ELECTRICL RELAY Thomas E. Meara, The Union Switch Swissvale, Pa., assigner to & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application October 17, 1944, Serial No. 559,076

(Ci. 17E- 339) Claims. l

My invention relates to electrical relays, and particularly 'to electrical relays of the direct current polarized type. More particularly, my present invention relates to polarized relays having two oppositely polarized armatures so arranged that both armatures will be released or one armature or the other will be picked up according as the relay is deenergized or is energized by current of one polarity or the other.

vOne object of my invention is to provide a relay of the type described with means for positively preventing either armature from moving toits attracted position for any rea-son when the other armature occupies its attracted position to thereby increase the safety of the relay against false 0peration.

Another object of my invention is to provide a polarized relay having increased immunity to false operation due to overenergization, lightning 'surges, and the like.

A further object of my invention is -to provide a relay of the type described which is simple to construct and maintain.

n accordance with my invention these objects are obtained by mounting the two armatures of the relay in close proximity, and by associating with the armatures suitable means for interlocking them in such manner that the picking up of either arma-ture locks the other armature in its released position.

Other objects and characteristic features of my invention will become apparent as the description proceeds.

I shall describe three forms of electrical relays embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a view partly diagrammatic and partly in isometric Drojection showing one form of relay embodying my invention. Figs. 2 and 3 are views similar to Fig. 1 showing modified forms of the relay illustrated in Fig. l.

Similar reference characters refer parts in each ofthe several views.

Referring first to Fig. 1, the relay here shown comprises a first magnetic circuit consisting of two magnetizable pole pieces la and 2a connected at their upper ends by a magnetizable backstrap 3a and provided at their lower ends with inwardly extending portions 4a `and 5a, and a second magnetic circuit consisting of two magnetizable pole pieces Ib and 2b connected at their upper ends by -a magnetizable backstrap 3b and provided at their lower ends with inwardly extending por- Itionsl 4b and 5b. Both magnetic circuits are ento similar ergized by a. common winding 8 which surrounds the ltwo back straps 3a and 3b between 'the .assoelated pole pieces. The inwardly extending portions of both sets of pole pieces have their lower or pole faces ground to lie in the same plane for a purpose which will be made clear presently.

The relay also comprises a magnetizable armature la which is pivotally mounted adjacent one end for swinging movement toward and away from the pole faces of the pole pieces ia and 2a, and a magnetizable armature lb which i-s pivotally mounted adjacent one end for swinging movement toward and away from the pole faces of the pole pieces ib and 2b. The armature 7a is operatively connected with a plurality of contact fingers 9a and lila shown diagrammatically in the drawing, in such manner that, when the `armature is swung away from the pole pieces la and 2a the y nngers 9a and I 0a will engage fixed back contact members ila and I2a, respectively, `to close back contacts 9ct-i ia and I 0a-i 2a, but that, when the armature is swung toward the pole pieces, the contact fingers will then move out of engagement with the back contact members and into engagement with ilxed front contact members i3a and Ida to open the back contacts and close front contacts ila-i3d and Illa-ida, respectively. The armature 1b is similarly connected with contact fingers 9b and 10b which cooperate with fixed back contact members Hb and l2b or xed front contact members i322 and Hb to close iixed back contacts Shi-i ib and Mib-|21) or fixed front con- 4tacts 9b-i3b and Mib-Hb, according as the armature 'ib is swung toward or away from the pole pieces Ib and 2b. The physical structure of the contact fingers and associated fixed contact members and the means for connecting them with the associated armatures are well known, and need not therefore be described in detail herein.

The relay further comprises two L-shaped permanent magnets |5a and i513 for polarizing the armatures 'la and 1b. The magnet ia is secured at one end to the pole piece 2a, and the other end of this magnet extends underneath the armature 'la opposite the pole face of the pole piece 2a in such manner that, when the armature la is swung away from the pole pieces ia and 2a, it will be swung towardthe permanent magnet I5a, and vice versa. In actual practice, the armature 1a will be preventedfrom actually touching the pole pieces la and 2a, or the permanent magnet, by suitable non-magnetic stops or core pins not shown in the drawing.

The magnet I5b is secured to the pole piece 2b and cooperates with the armature 1b in the ysame the relay as a satana manner that the magnet @u is secured to the polel piece la and cooperates with the armature Associated with the armatures 'da and lb are suitable means for interlocking them in such manner that the picking up oi either armature will lock the other armature in its released posi tion. This interlocking means may have any desi'red construction and may be located at any convenient location, but as here shown this means comprises a non-magnetic interlocking dog it pivotally supported intermediate its ends between the ends of the armatures on a pivot pin Ill and cooperating at its ends with two laterally projectu ing ears lilla and lub secured to the two armatures la and lb, respectively. The pivot pin ill is se'H cured to a suitable non-magnetic supporting member disposed between the two pole pieces da and 2b, respectiv'iy.

Assuming that the upper end oi the permanent magnet flea is a north pole and the upper end oi the magnet ib is a south pole, as indicated by the letters N and S in the drawings, the operation of whole is as follows: Only when the .vinding i5 is deenergized, both armatures la and llb will drop, under the iniiuence of gravity, to the positions shown, so that the bach contacts 9th-lia, idd-Ma, Sib-lib and lith- Hb will all be closed, and under these conditions, a part of the flux from each of the permanent magnets 65a and lhb will pass lengthwise through the associated armature armature a torque which in holding the back contacts closed. The parts are so proportioned that this torque, together with the force of gravity, will be sucient to prevent the back contacts from bouncing open even though the relay is subjected to considerable shock or vibration.

l shall now assume that the winding d is energized in such manner that the pole pieces 2a and 2b become north poles and the pole pieces la and ib become south poles. Under these conditons the permanent magnet and electromagnet fluxes will buck each other in the armature 'la and will aid each other in the armature lb. As a result, as the magnetomotive force builds up in. armature lla, a point will be reached at which the upward pull exerted on the armature 'la by this flux will exceed the downward pull due to the permanent magnet flux and the force o gravity, and when this happens the armature 'la will swing armature it will act through the ear ith to rotate the dog i6 in a counterclockwise direction to the w position in which it cooperates with the ear l'a lili la or lb and will exert on the assists the pull of gravity' to lock the armature 'lla in its released position.

lit will be seen, therefore, that with a relay constructedin accordance with my invention when winding it is deenergized both armatures ld and ib will be held in their released positions by iiux from the permanent magnets, whereas when the winding is energized, one armature or the other will pick up, depending on the polarity oi the current supplied to the winding il. llt will also be seen that the armature which does piel: up will act to lock theK other armature in its released position.

Referring now to Fig. 2, l( have here shown a modied form of relay which differs irom that shown in Fig. l. principally in the fact that a single magnetic circuit is provided for controlling both armatures, which armatures as illustrated are pvoted at opposite ends or the relay instead of at the same end. These armatures could, however, be pivoted at the same end or the reiay if desired. As illustrated, the single magnetic circuit comprises two pole pieces 2i and 22 attached at their opposite ends to a baclrstrap 23. 'lihe energizing winding d i's mounted on the backstrap 23 between the two pole pieces 2i and 22. The pole pieces are made large enough to overlie both armatures and the two permanent magnets ia and ib are secured to the pole pieces al and 22, respectively, in laterally odset relation in positions to cooperate with the free ends of the armatures in the same manner as in Fig. 1. The interlocking dog it is plvotally supported from the pole piece 2i by means of a bracket 24 and pivot pin 2b in a position which is laterally between the two armatures approximately midway between their ends.

The operation of the relay shown in Fig. 2 is essentially the same as the operation of the relay shown in Fig. l, and will be obvious from the foregoing description and from an inspection of the drawing without further detail description.

Referring now to Fig. 3, the relay here illustrated comprises a magnetic circuit consisting of two parallel cores 25 and 26 connected together at their upper ends by a backstrap 21, and provided at their lower ends with enlarged pole pieces 2@ and 29 to which the L-shaped permanent magnets Ilia and i5?) are respectively attached. The

toward the pole pieces ia and 2a to thereby open the back contacts dor-ila and lila-42a and to close the front contacts 9ct-i3d and lila-Ma. The armature lb, however, will be held more strongly in its released position, and this will be true even though the energization of winding B is increased to many times its normal value. The picking up of the armature la will act through the ear I8a to rotate the interlocking dog I6 in va clockwise direction as viewed in Fig.' 1 to a po,-

sition in which it will just clear the upper face of the ear l8b attached to armature 1b, and consequently the armature 1b, in addition to being held in its released position by the pull of gravity and the combined uxes due to the electromagnet and permanent magnet traversing this armature, will be effectively locked in its released position.

If the winding B is energized in such manner that the pole pieces 2a and 2b become south poles and the pole pieces la and ib become north poles, the armature 'lb will then pick up and the armature 'la will remain in its released position, as will be obvious. Furthermore, the picking up of the cores 25 and 2t carry the usual operating wind ings 6a and db.. The two magnetizable armatures la and 'lb are plvotally mounted end to end in such manner that the armature 'la is free to swing between the pole piece 2B and the permanent magnet a and that the armature 1b is free to swing between the pole piece 29 and the magnet leb. The confronting ends of the armatures are in good magnetic transfer relationship, and carry interlocking means effective upon the movement of either armature toward the associated pole piece to prevent the other armature from moving toward the associated pole piece. As illustrated, these interlocking means comprise two similar arms 3l and 32 attached to the armatures la and 1b, respectively, and provided with stop pins 3 la and 32a so disposed that when either armature is picked up it will move the associated stop pins into engagement with the other stop pins and thus act to prevent the other armature from picking up. The armatures 1a and 1b may operate contacts in the same manner as in Figs. 1 and 2. The permanent magnets are arranged so that their upper ends both have the same traverses the two armatures in series the operation of the relay as a whole is essentially the same as that of the relays shown in Figs. 1 and 2. That is to say, when the windings 6a and 8b are both deenergized, both armatures will occupy their released positions as shown. When, however, the windings 8a and 8b are energized, one armature or the other will pick up depending on the polarity of the current, the other armature under these conditions being held down bothv by the attraction of the associated permanent magnet and also by the action of the interlocking means comprising the stop pins 3la and 32a.

Although I have herein shown and described only three forms of electrical relays embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. A relay comprising two pairs of pole pieces, means including an energizing winding and a back strap for supplying ux to the polevpieces of both pairs, two armatures one pivotaliy mounted for swinging movement toward and away from the pole pieces of each pair, two permanent magnets one secured directly to the pole piece located at the free end of each armature and having its one pole disposed in such a position with respect to the associated armature that when it is swung away from the associated pole pieces it will be swung toward said one pole of the associated magnet, and mechanical means effective upon the picking up of either armature for locking the other armature in 'its releasedposition.

2. A relay comprising two magnetic circuits each comprising a pair of pole pieces connected to a backstrap, an energizing winding surrounding said backstraps for reversibly supplying flux to both magnetic circuits, two armatures one pivotaliy mounted at one end for swinging movement toward and away from. the pole pieces of each pair, two permanent magnets one secured directly to the pole piece located at the free end of each armature and having its one pole disposed in such a position with respect to the associated armature that when it is swung away from the associated pole pieces it will be `swung toward said one pole of the associated magnet, said permanent magnets being magnetized to cause said armature to respond to currents oi' opposite polarity in said winding, and mechanical means eiiective upon the picking up of either armature for locking the other armature in its released position.

3. A relay comprising two magnetic circuits each comprising a pair of pole pieces connected to a backstrap, an energizing winding surrounding said backstraps for reversibly supplying ux to both magnetic circuits, two armatures one pivotally mounted at` one end for swinging movement toward and away from the pole pieces oi.' each pair, two permanent magnets one secured directly to the pole piece located atthe free end of each armature and having its one pole disposed in such a position with respect to the assoits attracted including a back strap,

elated amature that when it is swung away from the associated pole pieces it will be swung toward said one pole of the associated magnet, said permanent magnets being masnetized to cause said armature to respond to currents o! opposite polarity in said winding, and an interlocking dog pivotaliy, supported intermediate its ends between said aimatures and cooperating at its ends with two laterally projecting ears secured to the two armatures respectively in such manner that movement of either armature to its picked-up position will :act through the associated ear to rotate said dog to a positionV in which it cooperates with the other ear to lock the other armature in its released position.

4. A relay comprising two pole pieces secured to a backstrap surrounded by an energizing winding, two armatures pivotaliy supported side -by side at their opposite ends underneath said pole pieces for swinging movement toward and away from said pole pieces, two permanent magnets one secured to each pole piece and having its one pole disposed in such a position with respect to the end of the armature which is free to swing toward and away from such pole piece that when it is swung toward the pole piece it will swing toward said one pole of the associated magnet, and mechanical means effective upon the picking up of either armature for locking the other armature in its released position.

5. A relay comprising two pole pieces secured to a backstrap surrounded by an energizing winding, two armatures pivotaliy supported side by side at their opposite ends underneath said pole pieces for swinging movement toward and away from said pole pieces, two permanent magnets one secured to each pole piece and having its one pole disposed in such a position with respect t0 the end of the armature which is free to swing toward and away from such pole piece that when it is swung toward the pole piece it will swing toward saidone pole of the associated magnet, andan interlocking dog pivotaliy supported intermediate its ends between said armatures and cooperating at its ends with two laterally pro jecting ears secured to the two armatures respectively in such manner that movement of either armature to its picked-up position will act through the associated ear to rotate said dog to a position in which it cooperates with the other ear to lock the other armature in its released position.

6. An electrical relay comprising two arma.- tures, means associated with said armatures and including a back strap, pole pieces, and an energizing winding for at same polarity to both said armatures. two permanent magnets one associated with each arma ture and connected to the flux supplying means so as to bias the associated armature to its released position, said magnets being arranged to produce uxes of opposite polarity in the two armatures'so that the one armature will move to position when and only when said winding is energized by current of one polarity and the other armature will move to its attracted position when and only when said winding is energized by current of the'opposite polarity, and mechanical means associated with said armatures and effective upon the picking up of either armature to mechanically lock the other armature in its released position.

7. An electrical relay comprising two armatures, means associated with said armatures and pole pieces, and an entimes supplying ux of the ergizing winding 'tor at times supplying ux of the same polarity to both said armatures, two permanent magnets one associated with each armature and connected to the flux supplying means so as to bias the associated armature to its released position, said magnets being arranged to produce fluxes of opposite polarity in the two armatures so that the one armature will move to its attracted position when and only when said winding is energized by current of one/.polarity and the other armature will move to its attracted position when and only when said winding is energized by current of the opposite polarity, and an interlocking dog pivotally supported intermediate its ends between said armatures and cooperating at its ends with two laterally projecting ears secured to the two armatures respectively in such manner that movement of either armature to its picked-up position will act through the associated ear to rotate said dog to a position in which it cooperates with the other ear to lock the other armature in its released position.

8. An electrical relay comprising magnetic circuit means including two spaced pole piece means, back strap means connecting the pole piece means, and two armatures extending between the two pole piece means, each armature having one end movable toward and away from one of the pole piece means, an electrical winding surrounding a portion of the magnetic circuit means and effective when energized to produce flux of the same polarity in both armatures, two permanent magnets, one magnet being associated with each armature and magnetically connected with the pole piece means with respect to which the armature moves, each magnet acting to bias its associated armature away from its pole piece means, the two `magnets being arranged to produce biasing iluxes of opposite polarlties in the two armatures so thatl when the winding is energized the flux produced by it will aid the biasing flux in one armature and oppose the biasing ux in the other, whereby one armature moves to its attracted position when and only when the winding is energized by current of one polarity and the other armature moves to its attracted position when and only when the winding is energized by current of the opposite polarity, and mechanical means associated with the armatures and effective upon the Y Number Picking up of either armature to mechanically lock the other amature in its released position.

9. An electrical relay as in claim 8, -in which said mechanical means includes an interlocking dog pivotally supported intermediate its ends between said armatures and cooperating at its ends with two laterally projecting ears secured to the two armatures respectively in such manner that movement of either amature .to its picked-up position will act through the associated ear to rotate said dog'to a position in' which it cooperates with the other ear to lock the other armature in'its released position.

10. An electrical relay comprising two magnetic circuits; each magnetic circuit including tlrst and second spaced pole pieces, a back strap connecting the pole pieces, an armature pivoted at one end adjacent said first pole piece and having its free end movable toward and away from said second pole piece, a third pole piece facing said second pole piece so that the free end of the armature moves between the second and third pole pieces, and means including a permanent magnet connecting the second and third pole pieces to polarize them oppositely; said permanent magnets being oppositely arranged on the two magnetic circuits so that the respective armatures areof opposite polarity, and a single electrical winding surrounding adjacent portions of the two magnetic circuits, each of which portions connects the first and second pole pieces of its associated magnetic circuit so that upon energization of said winding the flux produced thereby opposes the polarizing effect of one permanent magnet on its associated armature and aids the polarizing effect of the other.

THOMAS J. OMEARA.

REFERENCES CITED UNITED STATES PATENTS Name Date 1,734,851 Ellis NOV. 5, 1929 1,809,633 Lazlch June 9, 1931 1,822,496 Lazich Sept. 8, 1931 1,827,496 Lazich Sept. 8, 1931 1,959,562 Ashworth May 22, 1934 2,108,634 Wilms Feb. 15,1938 2,203,888 Ashworth June 11, 1940 

